Officially called Nitmiluk, the Aboriginal or Jawoyn name for the cicadas associated with the creation stories of the area, this stunning canyon formed by the Katherine River in Nitmiluk National Park is actually a series of 13 gorges, each separated by a jumble of boulders. The gorge is 12 km (7½ miles) long and in many places the red rocky walls are almost 230 feet high. During the wet season (November through to April), the gorge is full of raging water and saltwater crocodiles, but during the dry season you can hire canoes or take one of several cruises to explore the gorges. Rangers clear the river of dangerous crocodiles at the start of each season so you can also swim, if the harmless freshwater crocodiles don't bother you.